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c. G. KO PPITZ, AIR BREAK SWITCH.

APPLlCATION FILED JULY 9.1917.

1,320,870. Patented Nov. 4, 1919.

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. APPLICATION FILED JULY 9,\91T- I 1,320.8). Patented Nov. 4, 1919.

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AIR BREAK SWITCH. APPLICATION mzo JULY 9. 1917.

1,320,870. Patented Nov. 4; 1919.

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cam. G. xorrrrz, or GREENSBUBG, PENNSYLVANIA, ASSIGNOR T0 RAILWAY AND INDUSTRIAL ENGINEERING COMPANY, or GREENSIBURG, PENNSYLVANIA, A 00220- RATION OF PENNSYLVANIA.

AIR-BREAK SWITCH.

Specification of Letters Patent.

Patented Nov. 4, 1919.

Application filed July 9, 1917. Serial No. 179,559.

To all whom it may concern:

Be it known that I, CARL G. Korrrrz, a citizen of the United States of America, residing at Greensburg, in the county of Westmoreland and State of Pennsylvania, have invented certain new and useful Improvements in Air-Break Switches, of which the following is a specification.

The present invention relates to air break switches such as are used on high tension circuits and particularly to that class of switches which are automatically opened when a heavy overload or short circuit occurs on the line.

It is the particular object of my invention to produce an automatic trip mechanism that can be readily applied to exist ing non-automatic switches without any material change of construction and without changing the mode of operation of such existing systems.

For the purpose of illustrating the principal features of my invention I have shown. it as applied to a standard Burke horn gap switch of the type shown and described in the United States Patent No. 1,022,619.

In the drawings in which Figure 1 is an elevational view of a switch system embodying my. invention;

Fig. 2 an end view;

Fig. 3 an elevation of the trip mechanism with the casing in section;

Fig. 4 an elevation as viewed from the opposite side the casing being removed; and

Fig. 5 a section along the line A-A of Fig. 3.

l is a supporting post carrying at its top cross beams 2 and 3 which are suitably braced by V shaped arms 4 and 5. Across the beams 2 and 3 are connected the brackets 6, 7 and 8 carrying at an end thereof stationary insulators and supporting at the other end a rotary element. Since the switch units for all the lines are identical the description of one applies to each. 9 is the stationary insulator. 10 represents the rotary switch element comprising a base 11 pivoted on its supporting bracket 6 and two insulators 12 and 13. Stationary insulator 9 carries at its top a switch clip 14, one half of a horn gap switch 15 and a connection to the line 16. The rotary part 10, which rotates about the axis of insulator other half of the horn gap switch 18 and a connection to the line 18. These elements form no part of my invention and are merely recited to facilitate the understanding of the general operation of my invenion.

.The pivot 19 of each rotary element extends below the supporting brackets 6, 7 and 8 respectively. -All the rotary elements are lnterconnected by a rod 20 which makes loose connection to each by means of an arm 21 and a bolt 22 in any convenient way, so that all three switch units are simultaneously operated.

The projecting end of the pivot 19 of the central rotary element is coupled with the automatic trip mechanism 23 and through" the trip mechanism as intermediary with the operating rod 24. Through the coupling 25 the pin 19 is connected to shaft 26 of the trip mechanism for rotation therewith.

Having special reference to Figs. 3, 4 and 5, 25 is that half of the couplin 25 which is an integral part of shaft 26. he trip mechanism comprises principally an upper circular portion 27 and a lower circular portion '28 inter-connected by two stout pillars 29 and 30. The top portion 27 has a boss 31 and the bottom portion 28 a boss 32 for the purpose of providing sufficient bearing surface for the shaft 26 which rests on the bottom portion 28, the

the numeral 33 and the end of shaft 26 by the numeral 34. A strong coil spring 35 which surrounds shaft 26 is connected at one end to the frame of the trip mechanism and at the other end to the shaft, preferably to sleeve 36 which is secured to the shaft 26 by cap screws 37 and carries the trip arm 38. From the bottom portion 28 extends as an integral part thereof the stub 39 which has a hexagonal end portion for engagement with a socket coupling 40 on operating rod 24. To the lower end of rod 24 is attached a handle 41-for turning the rod. The handle is pivoted on a collar 42 and may be turned to lock the rod in a clip and spring actuated to normally hold it in one definite position, a latch connection between the primary and secondary trip arms, a latch connection betweenthe secondary trip arm and the frame and an electromagnet for breaking the last mentioned latching connection when the line current exceeds a definite value. I have found it preferable to make the disposition of all these parts as follows:

Between the pillars 29 and 30 and lntermediate the top and bottom portions 27 and 28 I secure to the frame a transverse plate 46 as by screws 46. This plate supports in proximity to pillar 30 the secondary trip arm 45 which has a sleeve 47 surrounding a brass bushing or other form of plvot 48. The sleeve is held against longitudlnal motion on pivot 48 by a washer 49 and bolt 50. The sleeve is surrounded by a coil spring 51 connected at one end to the plate 46 and at the other end to the sleeve 47 insuch a way that the trip arm 45 is normally restrained against motion to the left. To prevent turning of the trip arm 45 to the right or outside of the frame beyond a definite point, I have provided a stop shoulder 52 on the trip arm and a similar stop shoulder 53 on the plate 46. The trip arm 45 is provided directly adjacent sleeve 47 with a latch shoulder 54, preferable by securing a latch plate 55 of special hard steel, such as tool steel, to it. At its, free end the trip arm 45 is formed with another latch shoulder or edge 56 in a similar manner.

Between plate 46 and the bottom por tion 28 are placed two electromagnets 57 and 58, each having a plunger element. On the plate 46 is pivotally mounted between lugs 59 and 60 a latch plate 61. This latch plate is the main latch and has arms 62 and 63 extending directly over the two plungers. It is understood that plate 46 is provided with two apertures in alinement with the plungers so that the plungers, when they are pulled up by the magnetlc action of the solenoids of the magnets or either one of them, may strike the latch plate 61. The latch plate 61 which is likewise provided with a latching shoulder of tool steel 64 is normally held in such a position by a coil spring 65 and stops 62 and 63' that it locks trip arm 45. The primary trip arm 88 has at its free end a latch 66 which is locked against the latch shoulder 54 of the trip arm 45 when the switches are closed and trip arm 45 is in turn locked by the latch shoulder 64 of the main latch plate 61. Latch 66 is pivoted on the trip arm 38 and acted upon by a spring 66' to force its locking shoulder inwardly.

When an overload occurs on one or two lines of the circuit, one or both of the plungers are raised and deliver a blow against the latch plate 61, disengage the latch plate and thereby allow the powerful spring 35 to overcome the action of spring 51 so that trip arm 45 will yield until the latch engagement between trip arm 38 and trip arm 45 is broken. then free to swing and will under the action of spring 35 open the switches.

In order to minimize the mechanical effect of the action of the powerful spring 35 as the switches reach their open position, I have provided a shock absorber. While the specific nature of such shock absorber may assume various forms, I have found it expedient to attach a heavy rubber block 67 to pillar 29 by means of cap screws 68. As the switches reach their open position,

which is preferably positively determined by stop shoulders (not shown), the resilient action of the rubber block deadens the impact and prevents injury to the switches. It is of course feasible to counteract the violence of spring action by other means as by the conventional dash pot or countersprings adjacent the switches, but I have attempted to make the trip mechanism absolutely selfcontained to avoid changes of present switch structures as far as possible and the use of the rubber block has enabled me to carry out that idea satisfactorily.

To reset the switches and the trip mechanism it is only necessary to lift the handle 41 out of' locking engagement with plate 44, turn it to the left as far as it is possible, then turn it to the right again and lock it in its previous osition. By the turning movement of ro 24 to the left the whole frame of the trip mechanism is turned against the tension of spring 35, thereby winding up spring 35, until the latch shoulder 54 on the secondary trip arm 45 snaps behind latch shoulder 66 on the primary trip arm 38. By the subsequent turning movement of handle 41 to the right the switches are closed again. To facilitate the ready engagement of the latch shoulder 54 and latch '66 I have formed on trip arm 45 a cam 69 clearly shown in Fig. 5. As the frame of the trip mechanism is turned to the left, as above described, the cam will come into contact with the spring pressed latch 66 and force it outwardly. After the shoulder 54 has just passed the latch 66 will snap back behind the shoulder 54 and lock it.

The specific construction of the electromagnet is not material, since it may be carried out in various ways within the scope of my invention. I have provided means for adjusting the normal position of the plungers so that it may be set to be drawn into the coil at any predetermined strength of current passing through the coil, within the ordinary range of overload currents. From the lower end of the coils I have extended brass tubes 7 O and 71. These tubes The trip arm 38 is have a slot 72 (shown in Fig. 3) of considerable extent. The plunger elements have a lateral projection 73 passing outwardly through the slot 72 and a short. distance beyond the outer surface of tube 70. A shiftable ring 74 is attached to the tubes and adapted to be secured thereto in any desired position as by wing screws 7 5. The surface of the tube is provided adjacent the slot with a scale indicating current values. By moving the ring 74 upwardly and with it the plunger, the magnet may be set for any desired overload current.

The magnets 57 and 58 are preferably fed by the secondaries of series transformers as is usual. The wires are brought into.

the casing through terminal bushings 7 6' provided in the bottom portion 28 and in the bottom plate of the outside casing 77. Casing 77 surrounds the frame and thereby protects all the elements of the trip mechanism. It may be attached to the frame in any suitable manner as by screws 80, and latches 80 (shown in Fig. 2). 80" is a spacing leg on bottom portion 28.

To protect the upper bearing of shaft 26 against the Weather I form on the shaft 26 a flange 81 which is slightly recessed in its lower surface to fit over the, boss 31.

From the foregoing it is apparent that I have provided a trip mechanism which is substantially self contained in that it may be directly applied to standard manually operated switch systems in use without necessitating any changes in existing structures except such as may be readily made without disturbing material elements and without changing the mode of operation of the manual operating means.

It is further apparent that by the use of a secondary trip arm or intermediate latch I have accomplished the important result that the primary trip arm, which is necessarily actuated by a powerful s rin for opening the switches, may be easi y trlpped by a comparatively weak trip mechanism such as ordinary electromagnets of small ca acity.v

at I claim is 1. An automatic trip mechanism comprising a casing, a shaft eccentrically mounted 9n the casing and having means for makmg connection to a switch element, a spring connected to the shaft and the casing and tending to prevent relativemovement therebetween in one direction, a primary trip arm secured to the shaft, a secondary trip arm pivotally mounted on the casing and having a shoulder adapted to hold the primary trip arm under tension ,and lock it against movement, spring means actin on the secondary triparm and tending to cop it in locking position, a third trip arm pivotally mounted on the casing and having a shoulder adapted to lock the secondary trip arm against pivotal movement, spring means acting on the said third trip arm to hold it in looking position relatively to the secondary trip arm, electro-magnetic means for unlocking the third trip arm, and means on the casing for turning it about the said shaft.

2'. The combination with two alined rod portions, of a casing rigidly connected to one of said portions and having pivotal motion on the other of said portions, spring means connected to the shaft and the casing and tending to prevent relative motion therebetween in one direction, a primary trip arm secured to the shaft, a secondary trip arm pivotally mounted on the casing and having a shoulder adapted to hold the primary trip arm under tension and lock it against movement, spring means acting on the secondary trip arm and tending to keep it in looking position, a third trip arm pivotally mounted on the casing and having a shoulder adapted to lock the secondary trip arm against pivotal movement, spring means actin on the said third trip arm to hold it in 00king position relatively to the secondary trip arm, electro-magnetic means for unlocking thethird trip arm, and means for rotating the rod portion connected to the casing.

3. An automatic trip mechanism comprising a casing, a shaft eccentrically mounted on the casing and having means for making connection to a switch element, a powerful spring connected to the shaft and the easing and tending to prevent relative movement therebetween in one direction, a primary trip arm secured to the shaft, an

, abutment in the path of the said trip arm adapted to limit its motion and absorb the shock due to the force of the spring, a secondary trip arm pivotally mounted on the casing and adapted to lock the primary trip arm under tension, a spring tending to hold the secondary trip arm in looking position, a third trip arm pivotally mounted on the casing and adapted to lock the secondary trip arm in locking position, a spring tending to hold the third trip arm in looking position, and electromagnetic means for unlocking the third trip arm.

In testimony whereof, I afiix my signature.

CARL G. KOPPITZ. 

